Osteoporosis teriparatide
Osteoporosis is a serious post-menopause problem for many women, as bone density tends to reduce, increasing the risk of fractures. Treatments are available, but are often associated with severe side-effects.
Osteoporosis is a serious post-menopause problem for many women, as bone density tends to reduce, increasing the risk of fractures. Treatments are available, but are often associated with severe side-effects.
The bisphosphonate drugs, such as alendronate, reduce bone loss, but often cause serious gastrointestinal irritation and ulceration.
A new treatment developed by Eli Lilly, teriparatide, is a fragment of human parathyroid hormone, which is essential in the regulation of calcium and vitamin D within the body, as well as playing a pivotal role in bone remodelling. Although an excess of the hormone in the system can actually lead to bone loss, small amounts given daily by injection can increase bone formation. Teriparatide is recombinant human para-thyroid hormone 1-34 and, besides stimulating bone formation, it increases bone mineral density and restores bone architecture, unlike the bisphosphonates which reduce bone resorption while increasing bone mineral density.
In a comparative study with alendronate, 146 postmenopausal women with osteoporosis were given either once daily subcutaneous 40µg injections of teriparatide plus oral placebo, or 10mg oral alendronate plus placebo injection, over a median period of 14 months.1 After three months, teriparatide was shown to increase lumbar spine bone mineral density by 12.2%, compared with only 5.6% in the patients given alendronate, and also gave a significantly greater increase at the neck of femur. Furthermore, non-vertebral fracture incidence was lower with teriparatide.
The treatment has been evaluated in combination with HRT in women with severe vertebral osteoporosis.2 Fifteen patients were given teriparatide alongside HRT, and eight others HRT alone, for a year. Those given co-therapy showed an impressive response at the spine after two years, and a significantly positive metabolic calcium balance at one year. In the long term, activating the parathyroid hormone receptors proved the most effective treatment for osteoporosis.
Teriparatide has also been shown to be effective in reversing corticosteroid-induced osteoporosis. A 12-month randomised clinical trial was carried out in postmenopausal women with osteoporosis who were taking both corticosteroids and HRT.3 Those given the drug showed 33.5% improvement in bone mineral density in the lumbar spine, compared with just 9.8% for those on HRT alone.